Part of the "Buffy the Vampire Slayer" Scooby Gang is back together! Seth Green is filming his guest stint on "How I Met Your Mother" and reunited with his former co-star Alyson Hannigan on the set Friday.
The two sent tweets about their reunion excitement and tweeted photos with each other.
"How I Met Your Mother" airs Mondays at 8 p.m. ET on CBS.